ISL21080 Datasheet, PDF (6/10 Pages) Intersil Corporation – 300nA NanoPower Voltage References

ISL21080
Typical Performance Characteristics Curves
160
NO LOAD
140
120
100
1nF
80
10nF
60
40
20
100nF
010
100
1k
10k
100k
1M
FREQUENCY (Hz)
FIGURE 13. Z_OUT vs FREQUENCY
V_OUT = 1.5V, V_IN = 3.0V, I_OUT = 0mA, T_A = +25°C unless otherwise
specified. (Continued)
0
NO LOAD
-10
-20
-30
1nF
10nF
-40
-50
100nF
-60
-7010
100
1k
10k
100k
1M
FREQUENCY (Hz)
FIGURE 14. PSRR vs FREQUENCY
High Current Application
1.502
V_IN = 5V
1.500
1.502
1.500
V_IN = 5V
1.498
1.496
1.494
V_IN = 3.5V
V_IN = 3.3V
1.498
1.496
1.494
V_IN = 3.5V
V_IN = 3.3V
1.4920
5
10
15
20
25
30
35
I_LOAD (mA)
FIGURE 15. DIFFERENT V_IN AT ROOM TEMPERATURE
Applications Information
FGA Technology
The ISL21080 series of voltage references use the floating gate
technology to create references with very low drift and supply
current. Essentially, the charge stored on a floating gate cell is
set precisely in manufacturing. The reference voltage output
itself is a buffered version of the floating gate voltage. The
resulting reference device has excellent characteristics which
are unique in the industry: very low temperature drift, high initial
accuracy, and almost zero supply current. Also, the reference
voltage itself is not limited by voltage bandgaps or zener
settings, so a wide range of reference voltages can be
programmed (standard voltage settings are provided, but
customer-specific voltages are available).
The process used for these reference devices is a floating
gate CMOS process, and the amplifier circuitry uses CMOS
transistors for amplifier and output transistor circuitry. While
providing excellent accuracy, there are limitations in output
noise level and load regulation due to the MOS device
1.492
0
5
10
15
20
25 30
35
I_LOAD (mA)
FIGURE 16. DIFFERENT V_IN AT HIGH TEMPERATURE
characteristics. These limitations are addressed with circuit
techniques discussed in other sections.
Nanopower Operation
Reference devices achieve their highest accuracy when
powered up continuously, and after initial stabilization has
taken place. This drift can be eliminated by leaving the
power on continuously.
The ISL21080 is the first high precision voltage reference
with ultra low power consumption that makes it possible to
leave power on continuously in battery operated circuits. The
ISL21080 consumes extremely low supply current due to the
proprietary FGA technology. Supply current at room
temperature is typically 350nA, which is 1 to 2 orders of
magnitude lower than competitive devices. Application
circuits using battery power will benefit greatly from having
an accurate, stable reference, which essentially presents no
load to the battery.
In particular, battery powered data converter circuits that
would normally require the entire circuit to be disabled when
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FN6934.0
July 28, 2009